Many of today's laptop, notebook, desktop and other personal computers, as well as computer peripherals and other electronic products have receptacles or ports for receiving removable IC cards. Such cards typically conform to software and hardware specifications, including form factor standards, established by the Personal Computer Memory Card International Association (PCMCIA). IC cards may be used for various purposes: for example, they can supplement the semiconductor or disk memory of a personal computer, or can be used as a communications link or to store information or data for use by the host system or for reconfiguring the host system in response to information stored in the integrated circuits within the IC card.
A typical IC card, along the lines disclosed in U.S. Pat. Nos. 5,244,397; 5,319,516; 5,038,250; 5,242,310 and 5,196,994, is built around a rectangular, molded plastic frame for supporting and locating a substrate or printed circuit board (PCB) carrying integrated circuit packages. The frame may include one or more cross ribs providing additional strength as well as PCB support and locating surfaces. The frame protects the PCB assembly from mechanical damage and serves as an attachment means for the housing connectors, switches, battery holders, and so forth. A bus connector is typically attached to the forward edge of the PCB. The bus connector includes a connector block of molded plastic enclosing multiple contacts for electrically connecting the IC card circuit elements to the host system by way of the IC card port. Some IC cards include along the rear edge of the PCB an input/output (I/O) connector for receiving a communications cable harness. Like the bus connector block, the rear I/O connector is connected to circuit elements on the substrate.
IC cards of the prior art further include a housing or cover usually comprising a pair of opposed sheet metal panels mechanically or adhesively secured to the plastic frame and in some cases, to the bus and rear connector bodies as well.
A drawback of conventional IC cards is that the frame occupies a significant portion of the space within the card thereby limiting the usable area available for the substrate. Because IC cards must conform to established PCMCIA form factors (for example, 85.times.54.times.5 mm for Type I cards), the external package dimensions cannot be expanded to provide additional substrate area.
Accordingly, an overall object of the present invention is to increase the usable substrate area of a standard IC card in order to accommodate additional IC packages and other electronic components, and to do so without sacrificing the mechanical strength and structural integrity of the IC card.